Duct joint frame

Abstract

A plurality of flange members are positioned oppositely of one another on the ends of a pair of generally rectangular sheet metal ducts. The flange members are positioned in pairs on the adjacent ends of the ducts. The angular legs of corner pieces extend into the ends of the flange members to connect the adjacent flange members on the end of each duct so that four corner pieces connect the flange members to form a frame around the respective duct end portion. The oppositely positioned flange members on the adjacent duct end portions are sealingly secured together by clamping together the adjacent corner pieces. Each flange member is formed by a thin walled sheet member and includes a pair of legs angularly disposed relative to one another to form a plurality of wall sections. A first wall section terminates in a first leg end portion, and a second wall section terminates in a second leg end portion. The first and second leg end portions are spaced apart. The first and second wall sections are positioned in overlying relation to receive the duct end portion therebetween. The duct end portion overlies the second wall section which extends around and below the duct end portion to a stop on the second leg end portion. The stop engages a plurality of protuberances or dimples on the surface of the duct adjacent the duct end portion to prevent retraction of the duct end portion from the flange member. The first leg end portion forms an abutment shoulder, and the duct end portion engages the abutment shoulder. Thus, the duct is rigidly secured between the stop and the abutment shoulder, thereby, eliminating freedom of movement between the flange wall sections to provide a torsionally rigid connection of each flange member to the duct end portion that resists bending of adjacent flange members away from each other to prevent air leakage at the duct joint.

We claim: 
     
       1. A duct joint frame for connection to the end portion of a generally rectangular duct comprising, a plurality of flange members,   each of said flange members having a front wall, said flange members formed by a thin walled sheet of material including a first leg having an end portion and a second leg having an end portion,   said first leg end portion being laterally spaced from said second leg end portion,   said leg portions beng bent relative to one another to form a plurality of wall sections,   a first wall section terminating at said first leg end portion,   a second wall section terminating at said second leg end portion,   said first and second wall sections being positioned in overlying relation to receive an end portion of a duct therebetween,   said first wall section including an abutment shoulder for receiving and restraining forward advancement of the duct end portion between said first and second wall sections,   said abutment shoulder abutting a portion of said second wall section at a fixed distance from the front wall of said flange member,   said second leg end portion forming stop means for engaging protuberances on the surface of the duct adjacent the duct end portion to prevent retraction of the duct end portion from between said first and second wall sections, and   said stop means being laterally spaced a fixed dimension from said abutment shoulder to maintain the duct end portion rigidly secured between said stop means and said abutment shoulder with said duct end portion a preselected fixed distance from said flange member front wall and said duct end portion connecting said first leg end portion to said second leg end portion and rigidifying said flange member.   
     
     
       2. A duct joint frame as set forth in claim 1 which includes, said second wall section including a front wall extending upwardly from said abutment shoulder,   said front wall being positioned in rigid contact with said abutment shoulder,   said abutment shoulder being inturned to form a pocket extending the length of said flange member, said pocket being structurally reinforced by said front wall,   said pocket arranged to receive the duct end portion, and   said pocket being adapted to receive a sealant material retained in said pocket the length of said flange member to sealingly connect the duct end portion to said flange member.   
     
     
       3. A duct joint as set forth in claim 1 in which, said second leg end portion extends horizontally below the duct end portion to said stop means,   said stop means including an inturned edge portion extending the length of said flange member, and   said edge portion being engageable with the protuberances on the surface of the duct to prevent retraction of the duct end portion from said flange member.   
     
     
       4. A duct joint as set forth in claim 3 in which, said inturned edge portion rigidly engages the protuberances on the surface of the duct within said flange member, and   said inturned edge portion exerting a force upon the duct end portion to maintain a rigid connection of the duct with said flange member from said inturned edge portion a fixed dimension to said second wall section.   
     
     
       5. A duct joint as set forth in claim 1 in which, said second leg end portion extends horizontally below the duct end portion to form a locking wall,   said locking wall terminating in said stop means including an edge portion extending the length of said flange member, and   said edge portion exerting a force upon the duct end portion to maintain the duct end portion in fixed abutting relation with said frame member opposite said second wall section.   
     
     
       6. A duct joint frame for connection to the end portion of a generally rectangular duct comprising, a plurality of flange portions extending upwardly from the end portion of the duct,   each of said flange portions being formed by a thin walled member including a first leg having an end portion and a second leg having an end portion,   said first leg end portion being laterally spaced from said second leg end portion to form a channel having opposite open end portions,   said leg portions being bent relative to one another to form a plurality of wall sections,   a plurality of angular corner pieces for connecting adjacent flange portions for forming a frame around the duct end portion,   said corner pieces each having a body portion and a pair of leg portions extending angularly from said body portion, each of said leg portions having an upper edge portion and a lower edge portion,   said pair of leg portions arranged to extend into said open end portions of said flange portions to connect adjacent flange portions on the duct end portion,   a front wall section extending upwardly from said first leg end portion, said front wall section having an upper end portion,   said pair of corner piece leg portions extending into abutting relation with said front wall sections of adjacent flange portions on the duct end portions,   abutment means positioned oppositely of said upper end portion of said front wall section and in engagement with said corner piece leg portion for urging said upper edge portion of said corner piece leg portion against said front wall section,   a bottom wall section extending substantially horizontally from said front wall section,   said bottom wall section arranged to receive said lower edge portion of said corner piece leg portion, and   said bottom wall including a shoulder spaced from said front wall section and abutting said lower edge portion of said corner piece leg portion to maintain said lower edge portion in contact with said front wall section.   
     
     
       7. A duct joint assembly for connecting the end portions of generally rectangular ducts comprising, a plurality of flange portions extending upwardly from the end portion of a duct,   each of said flange portions being formed by a thin walled member including a first leg having an end portion and a second leg having an end portion,   said first leg end portion being laterally spaced from said second leg end portion to form a channel having opposite open end portions,   said leg portions being bent relative to one another to form a plurality of wall sections,   a plurality of angular corner pieces for connecting adjacent flange portions for forming a frame around the duct end portion,   said corner pieces each having a body portion and a pair of leg portions extending angularly from said body portion, each of said leg portions having an upper edge portion and a lower edge portion,   said pair of leg portions arranged to extend into said open end portions of said flange portions to connect adjacent flange portions on the duct end portion,   a front wall section extending upwardly from said first leg end portion, said front wall section having an upper end portion,   said pair of corner piece leg portions extending into abutting relation with said front wall sections of adjacent flange portions on the duct end portions,   abutment means positioned oppositely of said upper end portion of said front wall section and in engagement with said corner piece leg portion for urging said upper edge portion of said corner piece leg portion against said front wall section,   stop means positioned above said abutment means for receiving said upper edge portion of said corner piece leg portion above said abutment means,   a bottom wall section extending substantially horizontally from said front wall section,   said bottom wall section arranged to receive said lower edge portion of said corner piece leg portion,   said bottom wall section including a shoulder spaced from said front wall section and abutting said lower edge portion of said corner piece leg portion to maintain said lower edge portion in contact with said front wall section,   said corner piece body portion including an outer edge, and   a channel-shaped clamp forcibly slidable on said outer edge to a position closely adjacent said flange member front wall section to urge adjacent corner piece body portions toward each other to exert a sealing force upon said flange member front wall sections.   
     
     
       8. A duct joint assembly for connecting the end portions of generally rectangular ducts comprising, a plurality of receiving channels extending upwardly from the end portion of a duct,   each of said receiving channels including opposite channel open end portions,   a plurality of angular corner pieces for connecting adjacent receiving channels to form a rectangular frame around the duct end portion,   said corner pieces each having a body portion with a corner section and a pair of leg portions extending angularly therefrom,   said pair of leg portions each including an outer edge and an inner edge,   said pair of leg portions arranged to extend through said channel open end portions into said receiving channels to connect adjacent receiving channels on the duct end portion,   said leg portions being oppositely positioned with said receiving channels separating said leg portions,   said receiving channels including abutment means for engaging said leg portions adjacent said outer and inner edges thereof to rigidly secure said leg portions within said receiving channels so that said leg portions on adjacent duct end portions are maintained a preselected distance apart within said receiving channels,   said corner piece corner section including an outer flange edge extending on said corner piece corner section to a position closely adjacent said receiving channel, and   a clamp engageable with said corner piece corner sections on said outer flange edges of said oppositely positioned leg portions to compress together said adjacent corner piece body portions to exert a sealing force upon said receiving channels.   
     
     
       9. A method of connecting a duct joint frame to the end portion of a generally rectangular duct comprising the steps of, positioning a first wall section of a frame member in overlying relation with a second wall section to receive the duct end portion therebetween,   extending the duct end portion between the first and second wall sections with a first wall end portion spaced from a second wall end portion,   restraining forward movement of the duct end portion by abutting contact with a shoulder of the frame member adjacent the first wall end portion,   engaging the second wall section to protuberances on the surface of the duct adjacent the end portion thereof to prevent retraction of the duct from between the first and second wall sections,   eliminating freedom of movement of the first wall end portion relative to the second wall end portion by connecting the first wall end portion to the second wall end portion by the duct end portion, and   maintaining the duct rigidly connected to the first and second wall sections so that the duct end portion remains fixed in abutting relation with the frame member.   
     
     
       10. A duct joint frame for connection to the end portion of a generally rectangular duct comprising, a plurality of flange portions extending upwardly from the end portion of the duct,   each of said flange portions being formed by a thin walled member including a first leg having an end portion and a second leg having an end portion,   said first leg end portion being laterally spaced from said second leg end portion to form a channel having opposite open end portions,   said leg portions being bent relative to one another to form a plurality of wall sections,   a plurality of angular corner pieces for connecting adjacent flange portions for forming a frame around the duct end portion,   said corner pieces each having a body portion and a pair of leg portions extending angularly from said body portion, each of said leg portions having an upper edge portion and a lower edge portion,   said pair of leg portions arranged to extend into said open end portions of said flange portions to connect adjacent flange portions on the duct end portion,   a front wall section extending upwardly from said first leg end portion,   said pair of corner piece leg portions extending into abutting relation with said front wall sections of adjacent flange portions on the duct end portions,   said rear wall section including a bent portion turned inwardly toward said front wall section into abutting relation with said corner piece leg portion to securely hold said corner piece leg portion against said front wall section,   a bottom wall section extending substantially horizontally from said front wall section,   said bottom wall section arranged to receive said lower edge portion of said corner piece leg portion, and   said bottom wall including a shoulder spaced from said front wall section and abutting said lower edge portion of said corner piece leg portion to maintain said lower edge portion in contact with said front wall section.   
     
     
       11. A duct joint frame for connection to the end portion of a generally rectangular duct comprising, a plurality of flange members,   each of said flange members being formed by a thin walled sheet of material including a first leg having an end portion and a second leg having an end portion,   said first leg end portion being laterally spaced from said second leg end portion,   said leg portions being bent relative to one another to form a plurality of wall sections,   a first wall section terminating at said first leg end portion,   a second wall section terminating at said second leg end portion,   said first and second wall sections being positioned in overlying relation to receive an end portion of a duct therebetween,   said first leg end portion overlapping a portion of said second wall section to form an abutment shoulder for contacting the duct end portion,   said second leg end portion forming a stop for engaging protuberances on the surface of the duct adjacent the duct end portion to maintain the duct end portion in abutting relation with said abutment shoulder to prevent retraction of the duct end portion from between said first and second wall sections, and   said stop means on said second leg end portion and said abutment shoulder on said first leg end portion being connected by the duct end portion to provide a rigid connection of said flange member to the duct end portion.   
     
     
       12. A duct joint frame as set forth in claim 11 which includes, a front wall extending upwardly adjacent said abutment shoulder,   a locking wall extending horizontally from said front wall to said second leg end portion,   said abutment shoulder extending downwardly between the duct end portion and said front wall into overlapping relation with said locking wall, and   said abutting shoulder being securely engaged on opposite sides by said front wall and the duct end portion and supported by said locking wall to rigidly connect the duct end portion to the flange.   
     
     
       13. A duct joint frame as set forth in claim 11 in which, said abutment shoulder extends the length of said flange member,   said abutment shoulder projecting downwardly from said first leg end portion into surrounding relation with the duct end portion and terminating in an edge portion positioned below the duct end portion, and   said abutment shoulder contacting the duct end portion along the entire length of said flange member to rigidly retain the duct end portion therein.   
     
     
       14. A duct joint as set forth in claim 11 which includes, a front wall extending upwardly adjacent said abutment shoulder,   said abutment shoulder being positioned in rigid contact with said front wall,   said abutment shoulder extending downwardly in an arcuate configuration to an edge portion projecting away from said front wall,   said abutment shoulder forming a pocket extending the length of said flange member,   said pocket arranged to receive the duct end portion, and   said pocket being positioned at said front wall for receiving a sealant material extending longitudinally the length of said flange member and transversely from said abutment shoulder to said stop to sealingly connect the duct end portion within said flange member.   
     
     
       15. A duct joint as set forth in claim 11 in which, said second leg end portion extends horizontally below the duct end portion to said stop means,   said stop means including an inturned rebent portion having an upper leg folded in overlying relation with said second leg end portion and terminating in an edge portion extending the length of said flange member, and   said edge portion being engageable with the protuberances on the surface of the duct to prevent retraction of the duct end portion from said flange member.   
     
     
       16. A duct joint as set forth in claim 15 which includes, a sealant material in said flange member filling the space between said abutment shoulder and said edge portion of said inturned rebent portion,   said sealant material surrounding in sealing contact the surface of the duct within said flange member,   said edge portion of said inturned rebent portion contacting the protuberances on the surface of the duct thereby retaining said sealant material in said flange member, and   said abutment shoulder contacting the duct end portion to provide a rigid connection of said first and second leg end portions to the duct end portion to securely seal and retain duct end portion in said flange member.   
     
     
       17. A duct joint as set forth in claim 11 in which, said second leg end portion extends horizontally below the duct end portion to form a locking wall,   said locking wall including an inturned rebent portion extending upwardly toward said first leg end portion,   said inturned rebent portion arranged to receive the duct end portion and maintain the duct end portion in frictional engagement between said first leg end portion and said inturned rebent portion, and   said locking wall including a recess for receiving said first leg end portion to permit the duct end portion to extend over said locking wall into abutting relation with said abutment shoulder.   
     
     
       18. A duct joint frame for connection to the end portion of a generally rectangular duct comprising, a plurality of flange members,   each of said flange members being formed by a thin walled sheet of material including a first leg having an end portion and a second leg having an end portion,   said first leg end portion being laterally spaced from said second leg end portion to form a channel having opposite open end portions,   said leg portions being bent relative to one another to form a plurality of wall sections,   a plurality of angular corner pieces for connecting adjacent flange members for forming a frame around the duct end portion,   said corner pieces each having a corner section with a pair of legs extending angularly therefrom, said legs extending from said corner section in substantially the same plane,   said corner section including an offset portion with an end portion displaced laterally from said plane in which said legs extend from said corner section,   said corner piece legs arranged to extend into said open end portions of said channels to connect adjacent flange members on the duct end portion,   said corner piece corner section offset portion positioned externally of said channel open end portions,   a first wall section terminating at said first leg end portion,   a second wall section terminating at said second leg end portion,   said first and second wall sections being positioned in overlying relation to receive the duct therebetween with the duct end portion extending beyond said corner piece corner section offset portion,   said first leg end portion overlapping a portion of said second wall section to form an abutment shoulder for contacting the duct end portion,   said second leg end portion forming a stop for engaging protuberances on the surface of the duct adjacent the duct end portion to maintain the duct end portion in abutting relation with said abutment shoulder to prevent retraction of the duct end portion from between said first and second wall sections, and   said stop means on said second leg end portion and said abutment shoulder on said first leg end portion being connected by the duct end portion to provide a rigid connection of said flange member to the duct end portion and rigidify said flange member.